• The combatants continued to improve the technology for CW. In early 1916, both the French and the Germans began firing gas shells out of conventional artillery, and the British began to use gas barrages on a large scale the next year. Artillery shells could not achieve the gas concentrations provided by cylinders, but they could reach far back into enemy lines, reducing the risk of gas exposure to “friendly” forces.

While the Allies had at first lagged the Germans in developing new chemical weapons, they soon came up with innovations of their own. The first was the British “Livens Projector”, invented by Captain William H. Livens, a British Army officer who took a personal interest in finding new and more effective ways to kill Germans.

The “Livens Projector” was simply a metal pipe about a meter or so long that was buried in the soil at a 45-degree angle. Large numbers of the projectors were set up in banks. Each projector was loaded with a drum containing about 14 kilograms (30 pounds) of gas, and the bank of projectors was fired by an electrical charge, sending the drums tumbling through air for a range of over a kilometer and a half (about a mile). Each drum contained a bursting charge to blast it open when it landed near enemy trenches, dousing the enemy with gas with little warning. The Livens Projector was cheap, crude, and extremely effective, since it could be used in mass numbers to produce an overwhelming, terrifying barrage. It was first used at the Battle of Arras on 9 April 1917. As a witness observed:


The discharge took place practically simultaneously: a dull red flash seemed to flicker all along the front as far as the eye could reach, and there was a slight ground tremor, followed a little later by a muffled roar, as 2,340 of these sinister projectiles hurtled through space, turning clumsily over and over, and some of them, no doubt, colliding in flight.

About 20 seconds later they landed in masses in the German positions, and after a brief pause the steel cases were burst open by the explosive charges inside, and nearly fifty tons of liquid phosgene were liberated which vaporized instantly and formed a cloud that Livens, who watched the discharge from an aeroplane, noticed it still so thick as to be visible as it floated over Vimy and Bailleu villages.


The British became very competent at setting up and using massed Livens Projectors, and developed a variety of projectiles for the weapon. The Germans tried to copy it, but the Livens Projector gave the British an edge on the Germans in gas warfare and the Germans never quite caught back up.

• The Germans had another trick of their own, however. On the evening of 12 July 1917, the Germans fired shells into British trenches at Ypres, but when they burst the shells released a brown oily fluid, not a gas. The stuff had a horrible smell, something like rancid garlic or mustard, but it otherwise didn’t seem particularly offensive and caused only slight irritation to eyes and throat. Remarkably, given the paranoia over gas attacks, many British troops didn’t bother to put on gas masks. As the night wore on, they began to feel pain rising in their eyes and throats, and gradually suffered swelling and huge blisters wherever their skin had come into contact with the noxious fluid.

The results were horrendous, with all affected losing large patches of skin and many of the men blinded. Some died from the massive damage done to throat and lungs. The actual number of fatalities was low, but many of the victims were so badly hurt that they would not be fit to fight for months, if they ever recovered their health at all.

The Germans called their new weapon “Lost”, or “Yellow Cross” after the marking on shells, in contrast to the “Green Cross” that designated chlorine and phosgene. The French quickly named it “Yperite”, after its use at Ypres. The British codenamed it “HS”, for “Hun Stuff”, but its rank smell inspired another name that stuck: “mustard gas”.

Its formal name was “dichloroethyl sulfide”, and it had been discovered by accident by chemical researchers before the war, some of whom had been badly burned by it. Mustard was not used in its formulation, the smell was simply a coincidence, and was actually due to impurities that arose in its formulation. The pure agent actually had little or no smell.

Mustard was a “blistering agent”, or in formal medical terms a “vesicant” — in essence it caused chemical burns. It had actually been evaluated by the British some time earlier and rejected as insufficiently lethal. In fact, although mustard gas didn’t have the killing power of phosgene, it was still a very useful weapon. The Germans had realized that improved Allied gas masks and training had rendered chlorine and phosgene gas ineffective. Haber then put his skills to work to develop a chemical weapon for which a gas mask could offer no protection.

Mustard gas did not dissipate like the other gases. The oily fluid could persist for a long time and continue to cause misery and pain to anyone who came in contact with it, for example accidentally getting some of it on his boots and from there on his hands and face. It would freeze during the winter, and still be toxic when it thawed again in the spring. In fact, French citizens were still occasionally suffering chemical burns in the 1990s from stumbling across ancient dud mustard shells plowed up on old battlefields.

Mustard gas was a vile substance and manufacturing it was difficult and dangerous. The French were not able to begin full production of it until June 1918. The British built a large plant at Avonmouth to manufacture mustard gas. The gas would cost workers at the Avonmouth plant three deaths, a thousand burns, and endless illnesses, some of which would plague their victims all their lives.

The British Army did not obtain mustard gas until September 1918, and the Allies never seriously used mustard gas in combat. They made do with phosgene with a vengeance. In early 1918, the British responded to the German mustard gas attacks with dense clouds of phosgene to overwhelm gas masks, with the poison released from big cylinders on train cars rolled up behind the lines.

The Americans were laggards at chemical warfare. They set up a “Gas Service” after they entered the war in 1917, which led to the “Chemical Warfare Service (CWS)” in 1918. The US Army was not all that enthusiastic about CW, largely because frontline officers had noticed the Germans became particularly annoyed if they were gassed, responding with heavy artillery barrages.

• The Germans launched their last major offensive in the West in March 1918. After initial success, the offensive fizzled out, and the Allied armies, now heavily reinforced by the Americans, pushed back the Germans relentlessly. By this time many of the artillery shells fired contained gas, with the proportion as high as a third or even half. However, it hadn’t proven a decisive weapon and had done little more than make conditions worse for the soldiers in the trenches.

Gas could be highly effective if it were used against opponents who were not equipped to deal with it. As mentioned, the Germans used it with great effect against the Russians, inflicting what is now broadly estimated to be about 600,000 casualties, and in October 1917, the Germans used phosgene to break the Italian defensive line in Northern Italy at Caporetto. The unprepared Italians were sent into terrified flight and decisively defeated. In contrast, troops who were equipped and trained to deal with gas attacks would suffer relatively minimal casualties, though bundling up against gas was stifling and exhausting, and life in a poisoned landscape was demoralizing.

Yet the gas shells kept flying overhead. One small incident stands out. On 14 October 1918, the British fired their new mustard gas shells into German positions at a Belgian village named Werwick. One of the injured was an Austrian-born corporal named Adolf Hitler, who wrote vividly in MEIN KAMPF that at “about seven o’clock my eyes were scorching ,,, a few hours later my eyes were like glowing coals, and all was darkness about me.” He was evacuated back to Germany by train a few days later, blinded, burned, and seething over his humiliation and the humiliation of his beloved Fatherland.

An armistice was declared in November 1918, and the shooting stopped. Gas was estimated to have killed about 100,000 men and injured a million. The number of men killed by gas was small compared to the number killed by other means, but gas had played a particularly unpleasant role in the conflict. Gas shells and other delivery systems had been refined, as had defensive technologies and procedures. All the combatants had been preparing even nastier chemical weapons when the war ended.